import pgzrun

WIDTH = 642
HEIGHT = 642

board = Actor('board')
board.pos = 642 // 2, 642 // 2

nums = []
offset = 1
num_size = 160
for i in range(15):
    r = i % 4
    c = i // 4
    num = Actor(str(i + 1))
    num.pos = r * num_size + num_size / 2 + offset, c * num_size + num_size / 2 + offset
    nums.append(num)

def update():
    pass

def draw():
    screen.clear()
    board.draw()
    for n in nums:
        n.draw()

pgzrun.go()